Conventionally, air purifiers including a discharge device are utilized as means for decomposing and removing odor components, injurious components, and the like in air by plasma generated by discharge. Of the air purifiers, an air purifier of streamer discharge type can obtain high air purifying efficiency at comparatively low power consumption, and therefore, can be said as a technology suitable for performing decomposition of injurious components and deodorization.
For example, as indicated in Patent Document 1 (Japanese Patent Application Laid Open Publication No. 2002-336689A), an air purifier of streamer discharge type includes, as a discharge device, a discharge electrode having a plurality of needle-shaped discharge parts, a counter electrode having counter parts confronting the discharge parts, and the power source means for applying voltage to both the electrodes. With such an arrangement of the discharge device, when voltage is applied to both the electrodes by power source means, streamer discharge is performed between the electrodes to generate low temperature plasma. Then, active species (high-energy electrons, ions, radicals, other excitons, and the like) generated in association with the generation of the low temperature plasma are allowed to flow and be in contact with injurious components or odor components in the to-be-treated air. Thus, these components are decomposed and removed.